Not sure what to do with your Salesforce External Chatter licenses?
Besides using Chatter licenses for communicating within the Salesforce platform, with a little know-how you can combine Salesforce oAuth system with a custom website. This saves you the time and the pain from administrating a separate authentication system and you can do some really cool stuff. For example, let’s say you want to have a website where customer can find information about the status of their case or provide additional information to your team. Essentially you can create a light user portal.